1. Field of the Invention
The invention relates to devices used for treatment within various body cavities and, in particular, to treatment of intracranial aneurysms.
2. Description of the Prior Art
Approximately 25,000 intracranial aneurysms rupture every year in North America. The general method of treatments intracranial aneurysms are extravascular, intravascular and extra-endovascular. The extravascular treatment is comprised of invasive surgery or microsurgery of the aneurysm to preserve the artery. The extra-endovascular comprises invasive surgery to expose the aneurysm to perforate it from the outside and to use various techniques to occlude the interior to prevent rebleeding.
An intravascular treatment has recently been developed, using navigable microcatheters to implant a plurality of small coils and/or to apply an electrical current through a coil which occludes or partially occludes the aneurysm and which is then detached with the result that the aneurysm is entirely occluded and rebleeding prevented. Such detachable coils are known as GDC coils or Guglielmi Detachable Coils based upon technology described in U.S. Pat. Nos. 5,122,136 (1992); 5,354,295 (1994); 5,540,680 (1996) and others, which are incorporated herein by reference. Therefore for the purposes of this specification and claims a "GDC coil" shall be defined to mean any device having a detachable coil for endovascular placement and in particular shall include the devices disclosed in the foregoing patents
While the intravascular treatment of aneurysms or occlusion of a bodily cavities has been successfully treated with GDC coils, in some patient cases the multiple insertion of GDC coils in the aneurysm or cavity has been difficult, because of the size of the aneurysm or of the neck or entrance to the aneurysm and because of the number of coils which needed to be inserted and retained in the aneurysm. In the case of a large number of coils, or in the case of a large opening to the aneurysm, the possibility of one or more coils escaping into the vascular system increases. Disposition of the coil at an uncontrolled site can give rise to a potential uncontrolled and, perhaps, undesired occlusion.
Therefore, what is needed is some type of apparatus and method whereby multiple GDC coils may be employed in the vascular system or in other bodily cavities and either retained within the aneurysm or cavity or at least easily retrieved in the event that it should escape.